Control device



Sept. 2, 1941. c. P. PEPPER I CONTROL DEVICE Filed'March 20, 1940 Inventor: Oar! p. pepper", byfi nuyfjwln -Hi5 Attorney.

. that my mechanically operated Patented Sept. 2,1941

UNITED STATES" PATENT OFFICE I v I I comi zt zvrca cmepm, Fort Wayne, Ind., assignor .to

Electric Company, a corporation of New York Application March 20, 1940, Seriai'No. 324,989

My invention relates to a control device and more particularly to a mechanically operated magnetic switch.

An object of my invention is to provide an improved control device which is simple in construction, reliable in operation, and which can be readily manufactured.

Another object of my invention is to provide a control device which will operate with a minimum of friction and noise.

Further objects and advantages or my invention will become apparent from the following description referring to the accompanying drawing, and the features of novelty which characterize my invention will bepointed out with particularity in the claims annexed to and forming a part of this specification.

In the drawing Fig. 1 is an end view of a machine provided with my improved control device; Fig. 2 is a side elevation in partial section of the end of the dynamo-electric machine illustrated in Fig. 1; Fig. 3 is an end view of a modification of the control device illustrated in Figs. 1 and 2'; Fig. 4 is a sectional side elevation of the control device illustrated in Fig. 3; Fig. 5 is an end view 01' a modification of the control device illustrated in Figs. 3 and 4, and Fig. 6 is a side elevation of a portion of an end of a dynamo-electric machine provided with the control device illustrated in Fig. 5.

My improved control device is illustrated and' described in its application as a switch in the starting winding circuit of a dynamo-electric machine, but; it is, of course, to be understood magnetic switch may have application in a variety of ways and particularly wherever it is desirable to have an abrupt movement of the switch resulting from a slow movement of an actuating device. Referring to the drawing, in Figs. 1 and 2 I have illustrated my improved control device attached to a stationary member I 0 of a dynamo-electric machine, which control device may be used to control the starting winding. My improved control device includes a plurality of relatively movable magnets H and I2, magnetically associated with faces which are in'substantially parallel planes. Let us assume pole Ila to llb is a south pole.

nets repel each other tion as illustrated in In order to have the magwhen they are in the posi- Figs. 1 and 2, then, In must be a south pole and IN) a north pole. Then be a north pole.- Then The spring member 20 is in turn attached to A the base plate in any suitable manner. such as by eyelets 21. Since my control device is mounted 'on the stationary member of the dynamo-electric machine the spring member 20 has a hole In order to provide an actuating member which will cause limited movement of the magnet I! I have provided a centrifugal operating arrangement 23. suitable actuating mechabe used, it being. onlynec- 0 when th magnets are in alignment, that is, lustrated in Fig. 2, when the motor is in its sta- Ila. and 28b of tionary position. Thus the contacts I and I! are closed and the starting winding circuit is connected to any suitable source of supply. Upon rotation of the shaft 22 to a certain critical speed, weight members 26 will move outwardly overcoming the force of spring members 11, thus causing the collar member to move axially to the right. When the magnets are in a position illustrated in Fig. 2, like poles face each other and of repulsion therebetween to remain closed. However, moves to the right the the magnetic force causes the contacts as the collar member 24 spring member moves with it due to its natural resiliency. It will be seen, therefore, that at some critical point as the unlike poles approach each other, the magnetic force of attraction between the unlike poles will overcome the magnetic force of repulsion, thus causing the magnet II to abruptly move towards the magnet l2 until its travel is halted by contacting the stop member It. The spring member Il may be biased to either help or hinder this movement, or its normal position may be midway between the contact l1 and the stop It, depending upon the desired characteristics of the control device. In the use of the control device as illustrated in Figs. 1 and 2, it is desirable to have the magnets attract each other when they are in alignment and repel each other when they move out of alignment, but it is, of course, to be understood that this condition may be reversed, or the magnets may be so arranged that relative movement merely varies the magnitude of the magnetic force therebetwecn.

In Figs. 3 and 4, I have illustrated a modification of the control device illustrated in Figs. 1 and 2 which has particular application when one of the magnets is to be mounted on a rotatable body. In this construction I have found it desirable to have the magnets repel each other when in alignment. The control device includes a magnet ",with unlike poles Ila, 28b, which is mounted on a spring member 2| similar to the magnet II and the spring member ll, illustrated in Figs. 1 and 2. The spring member 29 is in turn supported on. a base plate lll which may be similar to the base plate ll iliustrated in Figs. 1 and 2. A movable contact member II is provided on the movable spring member 29 for cooperation 'with a stationary contact 32. This contact 32 is supported on the base 30 through a bracket member 33. However, instead of having a magnet similar to the magnet 28 for cooperation therewith, as is employed in the device shown in Figs. 1 and 2, I provide a cylindricaliy shaped magnet M which is magnetized with its annular unlike poles "a and 34b facing outwardly in a direction toward the poles the magnet 28. The cylindrical magnet 34 is supported on an axially movable collar member 35. In this application I have found it desirable to have the magnets so arranged that poles 28a and a are alike and 28b and b are alike so that the magnets will repel each other when they are in alignment. It will be seen, therefore, that if the collar magnet ll are actuated in an axial direction that the magnetic force between the two masnets will vary until at a critical point the attracting force will become stronger than the repulsive force, thus causing the magnet 23 to move in a radial direction and cause opening of the contacts ll, 32. The collar member I! may be moved in an axial direction in any suitable man- I lar embodiments of my invention,

member and the spirit and scope of circuit controlling device arr ner, such as by a centrifugal mechanism illustrated in Fig. 2. It will be seen, therefore, that with the control device as illustrated in Figs. 8 and 4, that a centrifugal may be applied to any suitable use, such as in the starting circuit of a dynamo-electric machine. With such a device there will be no rubbing contact between the centrifugal actuating mechanism and the switch member, thus providing for a minimum of noise and friction.

In Figs. 5 and 6 there is illustrated a modification of the control device shown in Figs. 3 and 4, which I have also found to have particularly efficient operation as a centrifugal switch for a dynamo-electric machine. In order to provide an arrangement for shielding the permanent magnets from the flux produced by the motor field windings, a substantially cylindrical magnetic shield It is employed. The shield has a portion 38a projecting inwardly so that the member 38 will effectively shield the permanent magnets. In addition to acting as a magnetic shield, I employ the member 36 as a support for the cont-acts and one of the magnets, so as to provide a control device which is simple in construction and which can be manufactured with a minimum of parts. Thus the magnet 2|! and movable contact ii are carried by a suitable resilient member 31 which is in turn mounted on the shield 10. The attachment may be made in any suitable manner, such as by bolts 38. Also, the stationary contact 32 is suitably carried by a metallic member 39 which is in turn mounted on the shield 38 and attached in any suitable manner, such as by bolts 40. A stop member ll is also mounted on the shield. In order to electrically insulate the contacts from the shield an insulating member 42 is provided which extends around the inside periphery of the shield. Insulating washers 43 are provided between the heads of each of thebolts and the shield. Thus, it will be seen that I have provided a member which accomplishes the functions of a magnetic shield and support, so that an improved and emcient control device obtains.

In view of the foregoing it will be seen that I have provided a control device which employs mechanically actuated magnets which is simple in construction, efficient in operation, and which may have a variety of applications and be particularly efficacious where it is desired to have an abrupt movement of the contact as a result of the slow movement of an actuating mechanism.

Although I have shown and described particu- I do not desire to be limited to the particular embodiments described, and I intend in the appended claims to cover all modifications which do not depart from my invention.

What I claim as new and desire to secure by Letters Patent of theUnited States, is:

1. A centrifugal control device including relatively movable magnets having poles substan-, tially facing each other, said first magnet having a cylindrical shape and being mounted for rotational and axial movement adjacent said second mentioned magnet, a centrifugal operating means for causing axial movement of said first magnet so as to vary the magnitude of the magnetic force beiwveen said magnets and to allow abrupt movement of said second magnet toward and away from said first magnet, and a ansed to be actudevice is provided which ated by the abrupt movement of said second magnet.

2. A control device for an electric apparatus including relatively movable contacts, means for actuating said contacts including permanent for shieldng said permanent magnets from the magnetic flux produced by the electric apparatus, said contacts being supported by said shield, and means for insulating said contacts from said shielding member. v

3. A centrifugal switch including a pair of magnets having pole faces lying in substantially parallel planes so as to produce a magnetic force between the poles of said magnets, a rotatable body, a centrifugally operated device mounted movement in a radial ugally operated device direction, being operatively connected with said first mentioned magnet so that.

- direction, and a circuit 3 controlling device arranged to be actuated by said radial movement of said second magnet.

between their poles, one of said magnets being mounted for rotational movement about an axis and axial movement along said axis, the other of said magnets being ment, means for causingaxial movement of said first mentioned magnet upon rotational movement thereof so as to vary the magnitude of the magnetic force between said magnets and to allow movement of said second magnet in a member.

CARL P. PEPPER.

mounted for radial move-' 

